Читать книгу Self-Sufficiency: Home Brewing - John Parkes - Страница 13

Following significant improvements in the efficiency of the steam engine in the mid-18th century, industrialization of beer became a reality. Further innovations in the brewing process came about with the introduction of the thermometer in 1760, closely followed by the hydrometer, a simple but invaluable instrument that allowed brewers to measure attenuation (a measure of how much sugar in the wort has been fermented into alcohol by the yeast).

The hydrometer transformed the brewing process of beer. Before its introduction, beers were brewed from a single malt: brown beers from brown malt, amber beers from amber malt, and pale beers from pale malt. With the help of the hydrometer, brewers were able to compare the yield from equal weights of different malts.

Brewers observed that pale malt, though more expensive, yielded around 50 per cent more fermentable extract per unit of weight than the cheaper brown and amber malts, making it more cost-effective. Once this fact was established, brewers switched to using mostly pale malt for all beer types, supplemented with a small quantity of highly-coloured malt to achieve the desired colour for darker beers.

All malt starts life as pale malt, and it is the kilning process that transforms both its colour and flavour. In general, none of these early malts were sufficiently shielded from the smoke involved in the kilning process, and consequently, early beers had a smoky component to their flavours. Evidence suggests that maltsters and brewers constantly tried to minimize the smokiness of their finished beer.

Writers of the period describe the distinctive taste derived from wood-smoked malts, and the almost universal revulsion it engendered. The smoked beers and ales of the West Country were famous for being undrinkable – locals and the desperate excepted. The following extract from Directions for Brewing Malt Liquors in 1700 goes some way to describing the general feeling:

‘In most parts of the West, their malt is so stenched with the smoak of the wood, with which ’tis dryed, that no stranger can endure it, though the inhabitants, who are familiarized to it, can swallow it as the Hollanders do their thick black beer brewed with buck wheat.’

The invention of the drum roaster in 1817 by Daniel Wheeler allowed for the creation of very dark, roasted malts that were free from the unpleasant smoky taint brought about by roasting over open fires. The externally-heated drum roaster was able to produce a range of dark malts suitable for contributing to the flavour of porters and stouts. The development of the drum roaster was prompted by a British law preventing the use of any ingredients other than malt and hops in beer; prior to this, colouring of beers had been achieved using alternative ingredients. Porter brewers, employing a predominantly pale malt grist, urgently needed a legal colourant, and Wheeler’s patent malt was the solution.